Various operations involving optical fibers require fine control over alignment, orientation and/or positioning. Such operations include, for example, splicing of fibers, positioning a fiber with respect a light source, and fiber orientation for purposes of visual examination or automated analysis. Misalignment of fiber cores during splicing, for example, can severely degrade the performance characteristics of the spliced fiber and possibly the system in which it is disposed.
A simple fiber used in many applications is depicted sectionally in FIG. 1. The fiber 100 includes a core 110 surrounded by a cladding 120. Ordinarily, the core 110 and the surrounding cladding 120 are substantially visually transparent. During alignment, light is directed into the core 110 and/or cladding 120. The core 110 has a refractive index differing from that of the cladding 120, and may also include a lasing dopant. In any case, most of the introduced light desirably propagates through the core. When two fibers are properly aligned, light traveling through the core of one fiber will be efficiently transferred into the core of the next fiber.
The yield from this labor-intensive process is low by today's manufacturing standards, and the skill of the operator splicing the fibers plays a role in the overall performance of the spliced fibers. Low yield coupled with the intense manual labor required by the alignment processes easily translates into high cost.
Accordingly, there exists a need for optical fibers capable of convenient and accurate positioning relative to other fibers or to lights sources and other equipment.